Update dependencies and add Helium appimage

- Refresh many lock entries in flake.lock with new revisions and hashes.
- Enable the Helium appimage in default, desktop, and laptop host
  configs; add
  comment sections for web browsers and disable Fluxer by default.
- Rename the affinity option description from “Steam” to “Affinity”.
- Refactor appimage handling: introduce a generic mkAppImagePackage
  helper,
  import individual packages, and expose per‑package enable options.
- Update fluxer.nix to use a configurable icon size and adjust install
  paths.
- Bump Helium to version 0.12.3.1, update its hash, and make its icon
  size
  configurable.
- Adjust Hyprland settings: comment out the split‑layout bind, set
  configType = "hyprlang", enable Xwayland early, move vfr to the debug
  section, and comment out dwindle pseudotile.

hosts/Garand-Desktop/system-modules.nix

@@ -42,6 +42,11 @@ _: {
   ventoy.enable = false; # Ventoy: New Bootable USB Solution with GUI support
 
   packages = {
+    /*
+    Web browsers
+    */
+    appImages.helium.enable = true; # Helium: Better ungoogled-chromium
+
     /*
     Container & Packaging
     */
@@ -76,6 +81,7 @@ _: {
     teams.enable = true; # Teams-for-linux: Unofficial Microsoft Teams client for Linux
     ferdium.enable = false; # Ferdium: All your services in one place built by the community
     notify.enable = false; # notify-client: Ntfy client application to receive everyday's notifications
+    appImages.fluxer.enable = false; # Fluxer: Discord alternative
 
     /*
     Productivity / Knowledge Management

hosts/Garand-Laptop/system-modules.nix

@@ -42,6 +42,11 @@ _: {
   ventoy.enable = false; # Ventoy: New Bootable USB Solution with GUI support
 
   packages = {
+    /*
+    Web browsers
+    */
+    appImages.helium.enable = true; # Helium: Better ungoogled-chromium
+
     /*
     Container & Packaging
     */
@@ -76,6 +81,7 @@ _: {
     teams.enable = true; # Teams-for-linux: Unofficial Microsoft Teams client for Linux
     ferdium.enable = false; # Ferdium: All your services in one place built by the community
     notify.enable = false; # notify-client: Ntfy client application to receive everyday's notifications
+    appImages.fluxer.enable = false; # Fluxer: Discord alternative
 
     /*
     Productivity / Knowledge Management

hosts/default/system-modules.nix

@@ -42,6 +42,11 @@ _: {
   ventoy.enable = false; # Ventoy: New Bootable USB Solution with GUI support
 
   packages = {
+    /*
+    Web browsers
+    */
+    appImages.helium.enable = true; # Helium: Better ungoogled-chromium
+
     /*
     Container & Packaging
     */
@@ -76,6 +81,7 @@ _: {
     teams.enable = true; # Teams-for-linux: Unofficial Microsoft Teams client for Linux
     ferdium.enable = false; # Ferdium: All your services in one place built by the community
     notify.enable = false; # notify-client: Ntfy client application to receive everyday's notifications
+    appImages.fluxer.enable = false; # Fluxer: Discord alternative
 
     /*
     Productivity / Knowledge Management